[PING] Re: RFR 8129976: RunFinalizationTest.java times out frequently

[Jaroslav Bachorik]

Could someone, please, take a look at this?

Thanks,

-JB-

On 9.7.2015 18:45, Jaroslav Bachorik wrote:
> Please, review the following test change
>
> Issue : https://bugs.openjdk.java.net/browse/JDK-8129976
> Webrev: http://cr.openjdk.java.net/~jbachorik/8129976/webrev.00
>
> The test, as it is now, most of the times does not test the desired
> functionality (that invoking GC.run_finalization DCMD actually runs
> finalization) because the preceding call to System.gc() will finalize
> the test object sooner. But without calling System.gc() it is non
> predictable when the test object will be eligible for finalization so we
> have to call System.gc().
>
> In the rare occasions when System.gc() induced finalization does not
> finish before invoking GC.run_finalization the test deadlocks because
> its locking logic is flawed.
>
> In order to make this test work I had to:
> a\ Switch from '@run testng' to '@run main/othervm'
> b\ Run the finalization testing code in shutdown handler - this seems to
> prevent the finalization happening prematurely after calling System.gc()
> while still making the test object eligible for finalization
> c\ Switch from ReentrantLock to a Phaser for synchronization
> d\ Make sure that the finalization is not carried out on the default
> "Finalizer" thread to rule out finalization due to System.gc()
>
> After these changes the test seems to be rather stable (ran 1000
> iterations in a tight loop without single failure).
>
> Thanks,
>
> -JB-